Interstate 90 through the Washington Cascades and across northern Idaho and western Montana will be affected, along with Interstate 15 in western Montana.

Snow levels will start out around 5,000 feet Sunday morning in the northern Rockies then fall Sunday night into Monday as colder air arrives, getting down to the valley floors across Idaho and Montana by Monday morning.

By late Monday into Monday night, snow levels will fall below 1,000 feet across western Washington southward into western Oregon.

Seattle, Wash., and the surrounding lowlands can get snow showers mixed with rain showers late Monday and Portland, Ore., can see a snow shower Monday night.

Temperatures across the Northwest will be abnormally cold into the middle of next week.

Several locations, including Seattle and Portland, will flirt with their record low temperatures both Tuesday night and Wednesday night.

AccuWeather.com meteorologists are forecasting nighttime temperatures to dip into the teens and 20s.